No real way to do this as of now. Only way you may be able to is if you save the message and then forward it at a later date. There are other solutions like dynoplex and repligo that allow you to store and view the documents on their server but you would have to delve into the features. I remember recently dynoplex announced support for SD card storage so you may want to check them out first

I need an economical way to save attachments and then be able to forward them (.doc and xcel)

I would like to also be able to store .doc and xcel files for later use on the sd card

The treo was very good at this and the bb seems to be lacking

any thoughts

Hi Frankster,
eOffice Standard will do the job for you. We support saving attachment as files to SD. See: http://dynoplex.com. If you wish to save some money on its purchase contact our customer care department, they have daily discounts.